In the literature various chemical reagents have been developed during the past century that are suitable for the preliminary identification of different illicit drugs such as Marquis, Liebermann’s, Simon’s. Color tests are an important tool for the preliminary identification of illicit drugs in spite of developments in instrumental technology and the increased portability of this technology which enables its use in the field. Color tests or spot tests are chemical tests that involve the reaction of a sample with a reagent or a series of reagents to produce a color or a change in color. The popularity of color tests arises from the fact that they are generally simple, quick, inexpensive, and quite sensitive. They are readily available and require minimal materials. These factors enable color tests to be used in the field and can be employed by those without extensive chemical backgrounds. A negative result for a color test is helpful, for instant in excluding a drug or class of drugs, depending on the test performed. In this study, we are going to describe a concept of utilization of various Keggin-type heteropolyacids of molybdenum and tungsten as suitable reagents for the preliminary identification of suspected illicit drug samples. Heteropolyacids of molybdenum and tungsten will be used as solution (spot test) as well as strip test for the screen identification of illicit drug samples. Moreover, the electroanalytical diagnostic experiments and ATR-FTIR measurements have been also utilized for identification of various illicit drugs.